The asbestos has been widely used as, particularly, building materials and there have been, as its uses, covering materials for covering a wall, sound-absorbing materials, insulation materials, molded slate materials and the like. However, separated asbestos fibers become thin fibrous dust, which may cause lung cancer, pulmonary fibrosis and mesothelioma, and have a harmful effect on human body and his or her health, so that any uses of the asbestos have been prohibited or limited.
Since the asbestos, however, has been also contained in the building materials of constructions constructed before the prohibition of its uses, users using the constructions may suffer any harmful effects on their health. Further, since any dispersion of the asbestos fibers may occur when these constructions are deconstructed, any harmful effect by the asbestos on the health of the persons for deconstructing them may become serious and contamination of environment by the asbestos or the like may also become serious. Thus, any means for treatment of rendering the asbestos harmless is widely required.
In the treatment method of rendering the asbestos harmless, safety is required for any persons of treatment while they do the treatment of rendering the asbestos harmless. Further, since there are larger quantities of the asbestos used in the construction constructed before the prohibition of its use and/or used in any other uses, it is hopeful that any costs required for apparatus and chemicals used for treatment of rendering the asbestos harmless or required for the treatment thereof are minimum ones.
The patent document 1 discloses a technology such that by using a treatment agent for asbestos containing phosphoric acid aqueous solution of 0.5 through 50% by weight and by spraying or applying such a treatment agent for asbestos against any building materials containing the asbestos, which covers the walls, ceiling and the like of the construction, the asbestos in the building materials is denatured so that its fibrous ones become bulked ones.
The patent document 2 discloses a technology such that using a treatment agent for asbestos in which hydrogen peroxide is added into an aqueous solution containing phosphoric acid of 30 through 50% so that the hydrogen peroxide becomes 3 through 5% by weight, such a treatment agent for asbestos is sprayed or applied against any building materials containing the asbestos, or the building materials are inserted into such a treatment agent.